Influence of organic pesticides on nematode and corn earworm damage and on yield of sweet corn.

Soil fumigants and nonvolatile pesticides increased growth and yield of sweet corn 'Seneca Chief' over that of control plants in a 3-year study. Nematicide treatments increased average yields by 31% over controls, but did not significantly affect the mean weight per ear. Increase in yield was related to control of Belonolaimus longicaudatus, Trichodorus christiei and Pratylenchus zeae. Nonvolatile chemicals more effectively reduced populations of B. longicaudatus and T. christiei than did soil fumigants. Aldicarb did not control Criconemoides ornatus. All pesticides controlled P. zeae. Pesticides did not control Heliothis zea effectively.